1. Field of the Invention
The present invention relates to a signal processing device, a signal processing method, and a program.
2. Description of the Related Art
In recent years, many types of signal recording devices that include a signal recording medium, such as a hard disk drive (HDD), and a microphone and that are configured to record sound or the like picked up by the microphone into the signal recording medium have been released. FIG. 7 shows an example of the configuration of a signal recording device 900. In the signal recording device 900, a sound pickup microphone 901 picks up sound or the like and converts the sound or the like into a digital signal, and a signal processing unit 907 performs appropriate signal processing on the digital signal. Then, under the control of a recording control unit 909, the signal on which the appropriate signal processing has been performed is recorded into an HDD 903, which is a recording medium.
In the case of a device such as the HDD 903, in which an actuator is driven by electric power supplied from a power source 905 so that the HDD 903 can perform various operations, a moving sound caused by driving of the actuator or the like is generated and such a moving sound is picked up as noise by the sound pickup microphone 901. As a result, the sound or the like picked up by the sound pickup microphone 901 contains such a moving sound of the device as noise, and the sound or the like containing the noise is recorded.
In order to solve the above-mentioned problem regarding noise, a noise reduction system for reducing noise generated in an HDD has been built on the assumption that “the operating state of an HDD can be acquired at a position outside the HDD” and a method for reducing noise generated in the HDD has been proposed (see, for example, Japanese Unexamined Patent Application Publication No. 2003-217275). In addition, Japanese Unexamined Patent Application Publication No. 2003-217275 describes a feature that a time during which noise is generated can be detected by extracting, with a sound pickup microphone attached to an HDD, noise generated in the HDD.